Abstract: Methods are provided for reducing non-specific interference in competitive protein binding assays employing as the labeled reagent a fluorescent conjugate of a hydrophobic ligand conjugated to a fluorescer, which in turn is bound to a water soluble polysaccharide carrier ("fluorescer conjugate reagent"). In order to reduce non-specific interference from physiologic samples, the fluorescent reagent is combined with a lipid substituted neutral support, under conditions which provides two binding fractions: a first weakly binding fraction which is relatively free of non-specific interference in a competitive protein binding assay employing physiological fluids; and a second fraction, which more strongly binds to the lipid substituted support.

Abstract: Methods and compositions for assaying for coenzymes having N-substituted 1,4-dihydropyridyl as the active portion of the prosthetic group. The conversion of NAD to NADH is widely measured both for determining NAD-NADH (including the analogs thereof) dependent enzymes and enzymes that can be coupled to NAD-NADH dependent enzymes, and for determining ligands or receptors in competitive protein binding assays. Antibodies specific for NADH in the presence of NAD are employed, providing enhanced fluorescence over the normal fluorescence of unbound NADH. By determining the rate of formation of NADH or the concentration of NADH, the analyte or enzyme of interest can be determined.

Abstract: Novel carboxyalkylated disopyramides (NORPACE.RTM.) are provided as precursors for conjugating proteins, either antigenic for the preparation of antibodies or enzymatic for the preparation of enzyme conjugates, which antibodies and enzyme conjugates find use as reagents in immunoassays. The combination of antibodies and enzyme conjugates provide for sensitive, accurate, rapid assays for disopyramide without interference from closely analogous compounds, such as methadone or disopyramides metabolites.